Wide Flange Beam - Effect of Fastener Hole Size in Flange
Wide Flange Beam - Effect of Fastener Hole Size in Flange
(OP)
I am designing a wide flange beam joined in the middle with flats on either side of the web and one on the top flange. How large can I (or should I) make the fastener for the top joint plate? There will be 1 hole each side of web and each side of joint. I am working with a W6 x 12lb beam, 1/2" bolts, but might consider 3/4" if the holes don't weaken the top tension loaded flange too much.






RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
When things are steep, remember to stay level-headed.
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
However, as haynewp correctly points out, the only way to make the connection work for sure is to look at all the failure modes and see what will work for your specific situation.
I suppose that if this were the only place this occured on the job and throwing an extra 30 bucks of steel at it makes the piece more than adequate by inspection, I might be inclined to do that. However, that method implies experience in connection design.
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
Thanks
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
If this is correct, I would shy away from the bolted connection. Why not weld the top plate to the top flanges? Even if the bolts provide the required moment strength, the holes might allow more slip and subsequent deflection than you want. I would also connect the bottom flanges, even if by (2) plates (1 on each side of the web) on the top of the bottom flange.
Is a full pen weld too expensive for this application?
Don't forget that on a cantilever it is the top flange that bracing is more critical for, not the compression flange.
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange
RE: Wide Flange Beam - Effect of Fastener Hole Size in Flange